The Balkans mourn 40 dead left by floodings

Bosnian Hanifa Masic (2rd L), 68, from the village of Zeljezno Polje, is conforted by young volunteers at a refugee collective center in Zepce.

Serbia has declared three days of national mourning and reported another death in the worst rainfall to hit the Balkan region in living memory. At least 40 people have died in Serbia, Bosnia and Croatia, after days of the heaviest rainfall since records began 120 years ago caused rivers to burst their banks and triggered hundreds of landslides.

Prime Minister Aleksandar Vucic said the death toll in the town of Obrenovac, southwest of Belgrade, alone had reached 14.

On Serbia's border with Bosnia, the mayor of Mali Zvornik said an "entire hill" was threatening to slide into the River Drina and flood the town and neighbouring Zvornik. Obrenovac was almost deserted, evacuated by police and soldiers on fears of a new flood wave.

In northern Bosnia, the Sava broke sandbag defences overnight and flooded several villages near the town of Orasje.

The government in Bosnia says more than 1 million people, or a quarter of the population, have been affected by the flooding and landslides, comparing the destruction to that of the country's 1992-95 war.

Soldiers, volunteers and energy workers continued to reinforce flood defences at the Kostolac coal-fired power plant east of Belgrade, where Energy Minister Slobodan Antic said the "crisis isn't over".

Officials said they believed the Nikola Tesla plant in Obrenovac, 30 km southwest of Belgrade, was largely out of danger. The plant covers roughly half of Serbia's electricity needs, but has been working at only partial capacity, forcing the country to boost imports.

Serbia's Vucic declared three days of mourning Wednesday-Friday. Bosnia held its own day of mourning today.